Load Balancing between two routers to same ISP - BGP

[vincent-n]

Currently I have two gateway routers (3620 and 2610) located on the same LAN with HSRP configured. The 3620 is primary and the 2610 is backup. These routers have their serial interface connected to the same ISP and I was told that the WAN links terminated on two different routers at the ISP's end. The only routing protocol that the routers run is BGP and are receiving BGP default routes from the ISP's routers (ie no HUGE BGP routing table). Internet traffic traverse on the 3620 only unless the 2610 becomes the primary router (then the traffic traverse on the backup WAN link). Now comes my problem:

- I was asked to look for ways to upgrade the primary link (currently at max 2mbps with a normal serial interface). Instead of upgrading the WAN link on the primary router, I was thinking of using the backup link on the backup router (2610)and somehow load balance the Internet traffic between these two routers. Has anyone got experience in this before? Possibly provide a working config of the routers? Show me some Cisco url so I can look up for myself? Thanks in advance for your help.

[thisisshanky]

You could use multiple HSRP groups and assign router1 as primary for group 1 and router 2 as primary for group 2. Half your users (vlans) will be configured with group 1 hsrp virtual address as default gateway, and the remaining half use group 2 hsrp virtual address as their gateway.

This way you can load share between the two links.

[ruwhite · Accepted solution]

Sure, you should be able to do this. There are a couple of options here. I'm assuming the reason you have hsrp configured on these two routers is that there are hosts directly attached to the ethernet of both routers--there are no routers between these two and the hosts, correct? If there are routers between these two and the hosts, then there are other options than these you'd want to explore.

But, given the above, take a look at:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_configuration_example09186a0080094e90.shtml

http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide09186a00801541c8.html

Either of these two should work, I'd think.

Russ.W